Optical cross-connect systems are used to switch optical signals in fiber optic networks. Optical cross-connect systems typically include mirrors for redirecting input optical signals from input fibers to output fibers. For example, some optical connect systems include an array of micro-electro-mechanical systems (MEMS) mirrors for reflecting input optical signals onto another array of MEMS mirrors that, in turn, reflect the optical signals onto the output fibers. The mirrors can be rotated using actuators to align the optical signals onto the appropriate fibers.
As optical cross-connect system sizes increase, monolithic MEMS arrays become less practical due to typical yield losses (e.g., caused by non-functioning or under-rotating mirrors or non-functioning collimators). For example, a mirror array for a 1024×1024 unit (1024 inputs and 1024 outputs) would need to be 32×32 (total 1024 mirrors) per MEMS die if there was no yield loss. To account for yield loss, the mirror array would likely be designed as a 36×36 mirror array (1296 mirrors). Due to aperture size of the mirrors (up to ˜1 millimeter (mm) in diameter) and their center-to-center pitch (typically ˜1 mm), a mirror can consume about 2 mm of linear length on each side of the array per mirror. A 150 mm or 200 mm diameter wafer could only support one 72 mm×72 mm die.